package cn.itcast.hotel.service.impl;

import cn.itcast.hotel.mapper.HotelMapper;
import cn.itcast.hotel.pojo.Hotel;
import cn.itcast.hotel.pojo.HotelDoc;
import cn.itcast.hotel.pojo.PageResult;
import cn.itcast.hotel.pojo.RequestParams;
import cn.itcast.hotel.service.IHotelService;
import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {

    @Autowired
    private RestHighLevelClient client;

    @Override
    public PageResult search(RequestParams params) {
        //1.准备request
        SearchRequest request = new SearchRequest("hotel");
        //2.准备DSL
        //黑马旅游网案例，第一是关键字搜索
        buildBasicQuery(params, request);
        //黑马旅游网,第二部是分页,
        int page = params.getPage();
        int size = params.getSize();
        request.source().from((page - 1) * size).size(size);
        //第三部，排序
        String location = params.getLocation();
        if (location != null && !"".equals(location)) {
            request.source().sort(SortBuilders.geoDistanceSort("location", new GeoPoint(location))
                    .order(SortOrder.ASC)
                    .unit(DistanceUnit.KILOMETERS));
        }
        //3.发送请求
        SearchResponse response = null;
        try {
            response = client.search(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        //4.解析响应
        return handleResponse(response);

    }

    @Override    //聚合查询多条件
    public Map<String, List<String>> filters(RequestParams params) {
        try {
            SearchRequest request = new SearchRequest("hotel");
            buildBasicQuery(params, request);
            request.source().size(0);
            buildAggregation(request);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);//json格式
            Aggregations aggregations = response.getAggregations();
            //根据名称获取品牌的结果
            Map<String, List<String>> result = new HashMap<>();
            ArrayList<String> brandList = getAggByName(aggregations, "brandAgg");
            ArrayList<String> cityList = getAggByName(aggregations, "cityAgg");
            ArrayList<String> starList = getAggByName(aggregations, "starAgg");
            result.put("brand", brandList);
            result.put("city", cityList);
            result.put("starName", starList);
            return result;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public List<String> getSuggestions(String prefix) {
        try {
            SearchRequest request = new SearchRequest("hotel");
            request.source().suggest(
                    new SuggestBuilder().addSuggestion(
                            "suggestions",
                            SuggestBuilders.completionSuggestion("suggestion")
                                    .prefix(prefix)
                                    .skipDuplicates(true)
                                    .size(10)
                    )
            );
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            Suggest suggest = response.getSuggest();
            //根据补全查询名称，获取补全结果
            CompletionSuggestion suggestions = suggest.getSuggestion("suggestions");
            List<CompletionSuggestion.Entry.Option> options = suggestions.getOptions();
            ArrayList<String> list = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option : options) {
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void insertById(Long id) {
        try {
            Hotel hotel = getById(id);
            HotelDoc hotelDoc = new HotelDoc(hotel);
            IndexRequest request = new IndexRequest("hotel").id(hotel.getId().toString());
            request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
            client.index(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteById(Long id) {
        try {
            DeleteRequest request = new DeleteRequest("hotel", id.toString());
            client.delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }

    private ArrayList<String> getAggByName(Aggregations aggregations, String aggName) {
        Terms agg = aggregations.get(aggName);
        List<? extends Terms.Bucket> buckets = agg.getBuckets();
        ArrayList<String> aggList = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            String key = bucket.getKeyAsString();
            aggList.add(key);
        }
        return aggList;
    }

    private void buildAggregation(SearchRequest request) {
        request.source().aggregation(
                AggregationBuilders
                        .terms("brandAgg")
                        .field("brand")
                        .size(100)
        );

        request.source().aggregation(
                AggregationBuilders
                        .terms("cityAgg")
                        .field("city")
                        .size(100)
        );

        request.source().aggregation(
                AggregationBuilders
                        .terms("starAgg")
                        .field("starName")
                        .size(100)
        );
    }

    private void buildBasicQuery(RequestParams params, SearchRequest request) {
        //1.原始查询算分的
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        //关键字搜索
        String key = params.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all", key));
        }
        //条件过滤  城市条件  品牌条件    星级条件  价格条件
        if (params.getCity() != null && !"".equals(params.getCity())) {
            boolQuery.filter(QueryBuilders.termQuery("city", params.getCity()));
        }
        if (params.getBrand() != null && !"".equals(params.getBrand())) {
            boolQuery.filter(QueryBuilders.termQuery("brand", params.getBrand()));
        }
        if (params.getStarName() != null && !"".equals(params.getStarName())) {
            boolQuery.filter(QueryBuilders.termQuery("starName", params.getStarName()));
        }

        if (params.getMinPrice() != null && params.getMaxPrice() != null) {
            boolQuery.filter(QueryBuilders.rangeQuery("price").gte(params.getMinPrice()).lte(params.getMaxPrice()));
        }

        //2.算分控制
        FunctionScoreQueryBuilder functionScoreQuery = QueryBuilders.functionScoreQuery(
                //原始查询
                boolQuery,
                //functionscore数组
                new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
                        //其中的一个functionscore元素
                        new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                //过滤条件
                                QueryBuilders.termQuery("isAD", true),
                                //算分函数
                                ScoreFunctionBuilders.weightFactorFunction(8)
                        )
                });
        request.source().query(functionScoreQuery);
    }

    private PageResult handleResponse(SearchResponse response) {
        SearchHits searchHits = response.getHits();
        long total = searchHits.getTotalHits().value;
        SearchHit[] hits = searchHits.getHits();//文档数组
        ArrayList<HotelDoc> hotels = new ArrayList<>();
        for (SearchHit hit : hits) {
            String sourcejson = hit.getSourceAsString();
            HotelDoc hotelDoc = JSON.parseObject(sourcejson, HotelDoc.class);
            Object[] sortValues = hit.getSortValues();
            if (sortValues.length > 0) {
                Object sortValue = sortValues[0];
                hotelDoc.setDistance(sortValue);
            }
            hotels.add(hotelDoc);
        }
        return new PageResult(total, hotels);
    }
}
